Below normal rainfall and above normal temperatures led to continued drought conditions in portions of northwest Iowa.
Every event with a place to put it; 4 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS DMX wrote it up.
Below normal rainfall and above normal temperatures led to continued drought conditions in portions of northwest Iowa.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Des Moines, IA wrote its last area forecast discussion before the first event at Apr 30, 10:46 PM CST, 1 hour 14 minutes earlier.
Area Forecast Discussion National Weather Service Des Moines IA 1146 PM CDT Fri Apr 30 2021 .DISCUSSION.../Tonight through Friday/ Issued at 211 PM CDT Fri Apr 30 2021 The quiet and gorgeous weather today belies a somewhat active forecast for the next several days. Highlights: - High fire danger on Saturday. See FIRE WEATHER discussion below for additional details. - Warm and windy Saturday, continued mild with increasing clouds Sunday. - Rain chances return at times late Sunday into Tuesday. - Cooler from Monday through the bulk of next week. Zonal steering flow will keep things dry for the next couple of days, while at the surface a weak cool front pushes across the Dakotas and western Minnesota tonight, then stalls just north/northwest of Iowa on Saturday. With the trough to our north and west and a large, retreating surface high pressure area well to our southeast, the pressure gradient will be maximized across Iowa and deep mixing will allow winds to turn to the southwest and increase substantially. Current forecast advertises sustained winds of around 25 mph during much of the day Saturday, with gusts to around 35 mph at times. Winds will likely be somewhat less in our far northern counties closer to the trough, however. These conditions should allow for maximized warming with temperatures soaring well into the 80s, and pushing 90 in parts of our north and west to kick off the month of May. The hot and dry conditions and strong winds will support a high fire danger as well, which is discussed in more detail in the FIRE WEATHER section below. On Saturday night winds will abate somewhat as mixing falls off with sunset, but remain organized and moderate from the southwest due to the persistent pressure gradient in place. On Sunday and Sunday night a subtle 500 mb shortwave trough will then move over the region, allowing the old surface front to slowly sag southeastward over our service area. The shortwave will also bring weak forcing and allow for the development of some showers and thunderstorms, primarily near the focal point of the slowly advancing frontal zone. Severe weather is not anticipated however. On Monday and Tuesday subsequent mid-level waves will move overhead, pushing the surface front further southeast past our area and resulting in lingering rain chances slowly clearing out to the southeast as well. There is uncertainty as to how long the rain will remain in our area before moving out, but certainly Monday appears likely to be a gray and damp day, and Tuesday may be much the same especially in our southeastern counties. This scenario will also promote a reinforcement of cooler air flowing into the region, with highs generally in the 60s for much of next week. && .AVIATION.../For the 06Z TAFS through 06Z Saturday night/ Issued at 1145 PM CDT Fri Apr 30 2021 Little change in thinking since 00z. Confidence in VFR conditions is high through the period with nothing beyond spotty mid and high level cloudiness. The biggest sensible weather impacts will be wind with LLWS developing shortly as winds aloft increase overnight. This will then lead to gusty SW winds into peak mixing by afternoon with some gusts over 30kt anticipated. LLWS may then develop once again toward the end of the period. && .FIRE WEATHER... Issued at 211 PM CDT Fri Apr 30 2021 Strong southwest winds are forecast on Saturday, with sustained speeds approaching 25 mph and gusts to around 35 mph at times. In addition temperatures will soar well into the 80s, perhaps approaching 90 in some northern and western areas, and pushing relative humidity values down into the 20s during the afternoon. Minimum RH values and forecast winds meet Red Flag Warning criteria, however, overall curing values are too low to warrant a warning given the relatively advanced state of most vegetation at this time of the season. Nevertheless, fire weather partners indicate some late-greening fuels remain quite susceptible to burning, particularly wild/long-stem grasses and some agricultural fuels, as well as brush and debris from the derecho last year, and these fuels may ignite easily and support quick spreading of any fires. This is particularly true given the distinct lack of recent spring rains, with some parts of Iowa experiencing one of their driest Aprils on record, mainly across the north/northwest third or so of the state. Given these various factors, and the assessment of an overall high fire danger on Saturday, have issued a Special Weather Statement to highlight the risk and will continue messaging it via other products and avenues as well. It is possible a Red Flag Warning could still be issued overnight for Saturday, and in any event burning is strongly discouraged. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && DISCUSSION...Lee AVIATION...Small FIRE WEATHER...Lee
Hazardous Weather Outlook National Weather Service Des Moines IA 336 PM CDT Fri Apr 30 2021 IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075- 081>086-092>097-012045- Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo- Pocahontas-Humboldt-Wright-Franklin-Butler-Bremer-Sac-Calhoun- Webster-Hamilton-Hardin-Grundy-Black Hawk-Crawford-Carroll-Greene- Boone-Story-Marshall-Tama-Audubon-Guthrie-Dallas-Polk-Jasper- Poweshiek-Cass-Adair-Madison-Warren-Marion-Mahaska-Adams-Union- Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-Wayne- Appanoose-Davis- 336 PM CDT Fri Apr 30 2021 This Hazardous Weather Outlook is for portions of central Iowa. .DAY ONE...This afternoon and tonight No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Saturday through Thursday High fire danger due to gusty winds, dry humidity and very warm temperatures can be expected on Saturday. Isolated to scattered thunderstorms are possible late Sunday afternoon into early Monday, but severe storms are not expected. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed. KLP
The national radar mosaic for the moment the first event began.
4 drought. Local standard time, as filed.
Severe drought persisted across portions of Emmet County during May. Precipitation remained below normal for the month with above normal temperatures.
Severe drought persisted across far western portions of Kossuth County during May. Precipitation remained below normal for the month with above normal temperatures.
Severe drought persisted across portions of Pocahontas County during May. Precipitation remained below normal for the month with above normal temperatures.
Severe drought persisted across portions of Palo Alto County during May. Precipitation remained below normal for the month with above normal temperatures.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Iowa in 2021Every state in 2021This day in weather historyWarnings in Iowa, May 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 957633, 957634, 957635, 957636.